The theory is it will keep traveler's speed down:

Is it just me or have other folks imagined music when driving over the various bumps glued to the road?

https://www.youtube.com/watch?v=lN8eEOz7PeY ]https://www.youtube.com/watch?v=lN8eEOz7PeY

There is also one in Lancaster, California with a part from William Tell.

jtk